Gay Men's Brain Same as Straight Women

LONDON (Reuters) - Gay men and straight women share some characteristics in the area of the brain responsible for emotion, mood and anxiety, researchers said on Monday in a study highlighting the potential biological underpinning of sexuality.

Brain scans also showed the same symmetry among lesbians and straight men, the researchers wrote in the Proceedings of the National Academy of Sciences.

Brain scans of 90 volunteers showed that the brains of heterosexual men and homosexual women were slightly asymmetric with the right hemisphere slightly larger than the left, Ivanka Savic and Pers Lindstrom wrote. The brains of gay men and heterosexual women were not.

Then they measured blood flow to the amygdala -- the area key for the "fight-or-flight" response -- and found it was wired in a similar fashion in gay men and heterosexual women as well as lesbians and heterosexual men.